Just got back from the 'Shack and here's what I learned:
I should not mess with things I don't understand if I don't have a backup plan.
Testing the voltage directly off the brass tip showed a voltage of 6.5V--there was no change with the cap loose or tight. Since I was able to taste a burnt flavor running with the cap loose that went away when I tightened the cap, I can conclude to my own satisfaction that the Xhaler is a system that relies on the load of the atomizer in use and the delrin cap to apply a load based resistance to the circuit. After a couple attempts trying to wire a connection between the Xhaler and the 510 atomizer that I could read the voltage, I finally got a reading on the Voltmeter that looked to be in the 5V range and I could hear what I thought was the sizzle of the atty working...but then lost the reading again...and couldn't get it back...Something was wrong...Oh there it is: I fried the battery spring. Test over. Called Drew and now I get to send back my Xhaler for replacement, in the meantime I get to ring in the New Year tonight without my Xhaler!

In the middle of writing this message, I took a call from a very good friend of mine who happens to be an Electrical Engineer for Tektronics...We had a good conversation ranging to a variety of topics including children and pending divorces and I told him about my failed attempt to test this circuit. I explained what I was trying to do and he said that it sounds like what the delrin cap does is that by being a partial conductor it does not decrease the maximum voltage but it changes the SHAPE of the current (observable on an oscilloscope) so that there is lower than expected voltage when the circuit is under load.
Today I learned some painful yet powerful lessons. I am currently experiencing the most powerful craving for an analog I've had in months, and my measly 510 mini battery is really not cutting it for me right now.
So I am officially DONE with this "controversy". Someone I trust implicitly in the field of electronics has given me a sufficient answer (but I will have him take a look at it to make sure it does work the way he hypothesized) and my personal experience is that I got an objectively better (there was a distinct difference in flavor) vaping experience with the Xhaler configured for 5V than under the 6V configuration on fresh batteries, and I have my own experience as well as the testimonials of dozens of other Xhaler owners that when the vapor production begins to tail off as the batteries run low, loosening the cap does in fact bring vapor production back up a bit--functionality that, regardless how it works, is not available on other more expensive models.
If you won't be satisfied with this....Frankly, MadGeoDuck, I don't care anymore. If you aren't going to buy an Xhaler, for whatever reason, that is your loss.
Happy New Year.
